Liferay7 BPM门户开发之40: Form表单的Action到Render的数据传递

在Form提交后的变量，很多情况是要展现在jsp页面中，这时Action到Render的变量传递就非常有用。

例如，您在数据库中添加了学生的详细信息。

为了实现这一需求，先创建Form表单（学生的细节，如姓名、出生日期等，通过action url来实现）。

当用户提交表单时，这些数据（学生信息）会在你执行CRUD操作的action方法添加。

添加完成后，需要把一些信息展现到jsp页面。

和v6.2不同的是，action方法里不需要写类似这样的语句：

actionResponse.setRenderParameter("XXX", 变量名);
actionRequest.setAttribute("XXX", 变量名);

举例说明

在Action阶段，我们提交了name变量，然后需要在Render阶段展现在JSP

Java代码

package com.lifiti.portlet;

import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.portlet.bridges.mvc.MVCPortlet;
import com.liferay.portal.kernel.util.ParamUtil;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.Portlet;
import javax.portlet.PortletException;
import javax.portlet.ProcessAction;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

import org.osgi.service.component.annotations.Component;

@Component(immediate = true, property = { "com.liferay.portlet.display-category=category.sample",
        "com.liferay.portlet.instanceable=true", "javax.portlet.requires-namespaced-parameters=false",
        "javax.portlet.display-name=com.lifiti.parts Portlet", "javax.portlet.init-param.template-path=/",
        "javax.portlet.init-param.view-template=/view.jsp", "javax.portlet.resource-bundle=content.Language",
        "javax.portlet.security-role-ref=power-user,user" }, service = Portlet.class)
public class FirstPortlet extends MVCPortlet {
    private static final Log _log = LogFactoryUtil.getLog(FirstPortlet.class.getName());

    @Override
    public void render(RenderRequest request, RenderResponse response) throws PortletException, IOException {
        String peopleName = ParamUtil.get(request, "name", "");
        String age = ParamUtil.get(request, "age", "");
        _log.info("peopleName by ParamUtil in render ==>" + peopleName);
        _log.info("age by ParamUtil in render ==>" + age);
        _log.info("age By RenderParameter in render ==>" + request.getAttribute("ageBySetParameter"));
        
        request.setAttribute("peopleName", peopleName);        
        
        super.render(request, response);
    }

    @ProcessAction(name = "send")
    public void ReceiveData(ActionRequest actionRequest, ActionResponse actionResponse) throws Exception {
        String name = ParamUtil.getString(actionRequest, "name");
        String age = ParamUtil.getString(actionRequest, "age");
        String phone = ParamUtil.getString(actionRequest, "phone");
        
        actionRequest.setAttribute("phone", phone);
        //actionResponse.setRenderParameter("ageBySetParameter", age);
        List<String> list = new ArrayList<String>();
        list.add("tom");
        list.add("cat");
        list.add("ketty");
        actionRequest.setAttribute("personList", list);
            
        _log.info(" 开始接收数据");
        System.out.println("FirstPortlet.java  name = " + name);
        System.out.println("FirstPortlet.java  age = " + age);
        System.out.println("FirstPortlet.java  phone = " + phone);
    }
}

jsp

<%@page import="com.liferay.portal.kernel.portlet.LiferayPortletMode"%>
<%@page import="com.liferay.portal.kernel.portlet.LiferayWindowState"%>
<%@ include file="/init.jsp" %>

<p>
    <b><liferay-ui:message key="com_lifiti_parts_ComLifitiPartsmvcportlet.caption"/></b>
</p>

<c:set var="submit"><liferay-ui:message key="com_lifiti_parts_ComLifitiPartsmvcportlet.submit"/></c:set>

<c:if test="${not empty phone }">
    Phone: ${phone} added successfully.
</c:if>
    
<c:if test="${not empty peopleName }">
    PeopleName: ${peopleName} added successfully.
</c:if>
<c:forEach var="x" items="${personList}">

　　<br> ${x}<br>        

</c:forEach>     
<portlet:actionURL var="sendURL" name="send">  
</portlet:actionURL>  
  
<form action="${sendURL}" method="post" name="fm">  
    <aui:input name="name" label="Name" id="name"/> 
    <aui:input name="age" label="Age" id="age"/> 
    <input type="text" name="<portlet:namespace/>phone" />  
     <input type="submit" value="${submit}"></input>  
</form>  

log：

FirstPortlet.java name = 王昕
FirstPortlet.java age = 1
FirstPortlet.java phone = 123
16:16:59,946 INFO [http-nio-8080-exec-7][FirstPortlet:32] peopleName by ParamUtil in render ==>王昕
16:16:59,947 INFO [http-nio-8080-exec-7][FirstPortlet:33] age by ParamUtil in render ==>1
16:16:59,947 INFO [http-nio-8080-exec-7][FirstPortlet:34] age By RenderParameter in render ==>null

v7.0中这种语句可以不用写：

actionRequest.setAttribute("phone", phone);
actionResponse.setRenderParameter("ageBySetParameter", age);

实际上，只需要2句就能完成数值传递：

String peopleName = ParamUtil.get(request, "name", "");
request.setAttribute("peopleName", peopleName);

直接使用ParamUtil很方便